John Gill explains it better than I ever could... Brother Glen
not to do mine own will, but the will of him that sent me;
that is, not to do his own will, as separate from his Father's, and much less as contrary to it; otherwise he did come to do his own will, which, as God, was the same with his Father's, he being one with him in nature, and so in power and will; and though his will, as man, was distinct from his Father's, yet not repugnant, but resigned unto it: and this will he came to do, was to preach the Gospel, fulfil the law, work miracles, and obtain the eternal redemption and salvation of his people. What the above Jewish writer
F14 objects to this part of the text is of very little moment: whose words are;
``moreover, what he says, "not to do mine own will, but the will of him that sent me", shows, that he that sent, is not one and the same with him that is sent, seeing the will of him that is sent, is not as the will of him that sends.''
It is readily granted that they are not one and the same person; they are two distinct persons, which sending, and being sent, do clearly show; but then they are one in nature, though distinct in person, and they agree in will and work. Christ came not to do any will of his own different from that of his Father's; nor do these words imply a difference of wills in them, much less a contrariety in them, but rather the sameness of them.